Linear alpha-olefin is widely used in important commercial substances such as comonomers, detergents, lubricants, plasticizers or the like, and in particular, 1-hexene and 1-octene are commonly used as comonomers for controlling density of polyethylene during preparation of linear low density polyethylene (LLDPE).
Such linear alpha-olefins have been mostly prepared through a Shell higher olefin process. However, since the method synthesizes alpha-olefins of various lengths together according to Schultz-Flory distribution, there is an inconvenience of needing an additional separation process in order to obtain a specific alpha-olefin.
In order to resolve this problem, a method of selectively synthesizing 1-hexene through a trimerization reaction of ethylene and a method of selectively synthesizing 1-octene through tetramerization of ethylene have been suggested. Further, various studies on catalysts enabling such selective oligomerization of ethylene have been undertaken.